Unable to explode object
Your object that you want to explode is one solid object. In order for it to explode you must first break it up into pieces.

I took the following steps:


Edit mode >Remove doubles
Object mode run cell fracture
Move object on layer one to a secondary/ unused layer and
move fractures to layer one
Add active rigid body physics to all fractures with collision margin
enabled at 1





Bake simulation then play the animation